title: Porin-incorporated liposome induces Toll-like receptors 2- and 6-dependent maturation and type 1 response of dendritic cell.
abstract: Porin of Shigella dysenteriae was incorporated in liposome (PIL) and presented to mouse splenic dendritic cells (DC). PIL up-regulated Toll-like receptor (TLR) 2 and TLR6 on DC, showing that co-expression of the two TLRs is involved in recognition of porin. Detection of myeloid differentiating factor 88 (MyD88)-TLR2 complex confirmed interaction between the two for triggering the downstream signaling, which ultimately led to TLR2-dependent nuclear translocation of nuclear factor-kappa B. PIL-induced expression of MHC class II (I-Ab), CD40 and CD80 showed maturation of DC, whereas up-regulation of intercellular adhesion molecule-1 and CCR7 implicated the capacity of splenic DC to migrate. Induction of messenger ribonucleic acid for the chemokines, macrophage-inflammatory protein (MIP)-1alpha, MIP-1beta and regulated upon activation, normal T cell expressed and secreted indicated a strong bias of PIL for type 1 polarization that was supported by the intracellular expression and release of tumor necrosis factor (TNF)-alpha and IL-12. Along with CD40 and CD80 expression, release of the cytokines of CD11c+ JAWS II cells was inhibited by TLR2 or simultaneous TLR2 and 6 knockdown showing that recognition of PIL by the two TLRs is essential for DC activation and type 1 polarization. The signaling pathway initiated upon recognition of PIL by the TLRs was MyD88 dependent as confirmed by inhibition of IL-6, TNF-alpha and IL-12 release of MyD88-knockdown JAWS II cells. The maturation and polarization of DC induced T(h)1 phenotype, as evident from proliferation, activation and IFN-gamma release of allogeneic CD4+ T cells in response to PIL-stimulated DC, thereby suggesting that the adjuvant activity of PIL can successfully bridge the innate and adaptive immunity.
authors.affiliation: Division of Immunology, National Institute of Cholera and Enteric Diseases, P-33, C.I.T. Road, Scheme XM, Kolkata 700 010, West Bengal, India.
authors.forename: Pallavi
authors.initials: P
authors.lastname: Banerjee
authors.forename: Amlan
authors.initials: A
authors.lastname: Biswas
authors.forename: Tapas
authors.initials: T
authors.lastname: Biswas
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002454:Cell Differentiation / Q000235:genetics / Q000276:immunology; D002460:Cell Line; D016207:Cytokines / Q000378:metabolism; D003713:Dendritic Cells / Q000378:metabolism* / Q000473:pathology; D015964:Gene Expression Regulation, Bacterial; D018189:Immunomagnetic Separation; D008081:Liposomes / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D053594:Myeloid Differentiation Factor 88 / Q000235:genetics; D018272:Porins / Q000235:genetics / Q000378:metabolism*; D012762:Shigella dysenteriae; D015398:Signal Transduction / Q000276:immunology; D018417:Th1 Cells / Q000378:metabolism; D051195:Toll-Like Receptor 2 / Q000235:genetics / Q000378:metabolism*; D051216:Toll-Like Receptor 6 / Q000235:genetics / Q000378:metabolism*; D014162:Transfection
chemical_list: D001426:Bacterial Proteins; D016207:Cytokines; D008081:Liposomes; C507780:Myd88 protein, mouse; D053594:Myeloid Differentiation Factor 88; D018272:Porins; D051195:Toll-Like Receptor 2; D051216:Toll-Like Receptor 6